1. Field of Invention
This invention relates generally to disposable containers for food products, and more particularly to a coated paper pouch for this purpose which is liquid impervious, yet is biodegradable and recyclable.
2. Status of Prior Art
Because of rising environmental concerns, in recent years stress has been placed on disposable containers that can be recycled. Thus a strong preference now exists for bags, cartons and other containers made entirely of paper, for these are biodegradable and can also be recycled. This is not true of those containers or other articles made entirely or in part of synthetic, polymeric plastic materials. Thus a cardboard carton lends itself to recycling, but not if it is lined with synthetic plastic films.
In recycling a paper carton or other paper product, use is made of broke beaters and pulpers which act to shred the waste paper and to produce a paper slurry for further processing. But if the paper product fed into the broke beater includes liners or tapes of synthetic plastic film material, the plastic will contaminate the slurry and render it unusable.
It is now common practice, when serving coffee, to supply cream therefor in a miniature plastic container. A typical container for this purpose is shown in FIG. 7 of the Tokuda et al. U.S. Pat. No. 4,903,842, the container being in the form of a small plastic cup having a rim to which is marginally adhered a plastic cover which can readily be peeled off the rim. In some cases, a metal foil cover is used.
Various forms of disposable, small plastic containers for dispensing food products are disclosed in the Fukushima U.S. Pat. No. 4,790,429, as well as in the Redmond U.S. Pat. Nos. 3,986,640 and 4,724,982. Where the containers disclosed in these patents are of plastic construction or formed of a laminate of plastic and metal foil, they are not biodegradable nor can they be recycled. And where the containers are made of plastics such as polystyrene, should they be incinerated to get rid of them, they will give off noxious fumes.
One well known form of pouch for a hot dog relish is made up of a laminate whose outer ply is a clear polyester film, the inner face of which is printed to identify the contents of the pouch. The inner face of the outer plastic ply is laminated by an adhesive to a foil ply, which in turn is laminated by an adhesive to a polyethylene inner ply. The polyester in this laminate is for exterior strength and tear resistance, the foil is included because it acts as a moisture barrier, and the polyethylene is for sealing purposes.
The manufacturing procedure for this well known pouch involves several steps and is a relatively costly process, for it requires the application of adhesives and the lamination of the polyester ply to the foil ply and then the lamination of the foil ply to the polyethylene ply. This plastic metal foil pouch is neither biodegradable nor can it be recycled.
The reason metal foil has heretofore been used in pouches for flowable food products in which the foil is laminated to a plastic film is that a film, even one of high strength, has some slight degree of porosity. It therefore exhibits a moisture-vapor transmission rate (MVTR), which is unsuitable for a food container, for it reduces the shelf life of the food.
Plastic pouches and those formed of plastic-metal foil laminate are in widespread use not only to package flowable food products such as salad oil, but also to package food powders such as seasoning, soft-drink and muffin mixes. Also packaged in such pouches are solid food products such as meat strips for dogs, candies and pretzels.
These pouches are satisfactory for long storage of their contents, but in no instance are they biodegradable and recyclable. Hence many millions of such pouches which are disposed of after they have served their purpose, now contribute toward environmental pollution.
Moreover, while plastic pouches and those formed of a plastic-metal foil laminate are provided with a weakened line to facilitate tearing of the pouch to provide access to the food product stored therein, they are nevertheless difficult to open, particularly if the user is a senior citizen or disabled.
My above-identified copending application discloses a recyclable paper pouch for enclosing a small supply of flowable material, such as ketchup, the pouch including a pocket for this material and a spout communicating with the pocket which leads to a rupturable outlet that when ruptured permits the flowable material to be expelled through the spout.
The concern of the present application is with paper pouches adapted to store either a solid or a flowable food product, and requiring no spout to expel the product from a pocket in the pouch.
Other prior art interest are the following U.S. patents:
Widiger et al. U.S. Pat. No. 3,558,330 PA1 Seiter U.S. Pat. No. 4,421,825 PA1 Gibbons et al. U.S. Pat. No. 4,698,246 PA1 Gibbons et al. U.S. Pat. No. 4,701,360 PA1 Lancaster et al. U.S. Pat. No. 4,795,665 PA1 Martin U.S. Pat. No. 4,806,398